diff --git a/Doc/c-api/exceptions.rst b/Doc/c-api/exceptions.rst
--- a/Doc/c-api/exceptions.rst
+++ b/Doc/c-api/exceptions.rst
@@ -347,6 +347,8 @@ is a separate error indicator for each t
    error checking.  *fd* should be a valid file descriptor.  The function should
    only be called from the main thread.
 
+   .. versionadded:: 2.6
+
 
 .. cfunction:: PyObject* PyErr_NewException(char *name, PyObject *base, PyObject *dict)
 
diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst
--- a/Doc/library/signal.rst
+++ b/Doc/library/signal.rst
@@ -204,6 +204,8 @@ The :mod:`signal` module defines the fol
    attempting to call it from other threads will cause a :exc:`ValueError`
    exception to be raised.
 
+   .. versionadded:: 2.6
+
 
 .. function:: siginterrupt(signalnum, flag)